They are being driven upwards by the climb in grain and oilseed prices as US crops weather the country’s worst drought since 1936, while the farming belts of Russia and South America suffer through similar water shortages.

What we are seeing represents the third major rally in global grain and oilseed prices in just half a decade.

Worse is to come, new research warns. World food prices look set to hit an all-time high in the first quarter of next year – and then keep rising, according to the analysis from Rabobank, a specialist in agricultural commodities.

By June 2013, the basket of food prices tracked by the United Nations could climb 15pc from current levels, according to the bank’s analysts.

“The coming year will see the world economy re-enter a period of agflation as grain and oilseed stocks decline to critically low levels, pushing the FAO [Food and Agricultural Organisation] Food Price Index above record nominal highs set in February 2011,” they say.